DE2438369A1 - PROCESS FOR THE MANUFACTURING OF SELF-EXTINGUISHING URETHANIUM-CONTAINING POLYISOCYANURATE FOAMS - Google Patents

Description

Our reference: O.Z. 30 7j5O Ls / Yes 67OO Ludwigshafen, August 8th, 1974

Process for the production of self-extinguishing urethane groups

containing polyisocyanurate foams

The invention relates to a method for the production of self-extinguishing, Polyisocyanurate foams containing urethane groups made from polyisocyanates and a polyesterol from an aliphatic dicarboxylic acid, an aliphatic diol and a halogen-substituted aromatic diol.

The production of polyurethane foams by reacting an organic polyisocyanate with a polyol, for example a polyester and / or polyether oil is known. The field of application of such foams is due to their flammability considerably limited. Attempts have therefore been made to chlorinate this deficiency by adding fillers such as antimony oxide Compounds such as the Diels-Alder adduct of hexahalogencyclopentadiene and maleic anhydride, or of phosphorus halogen compounds, such as tris-2-chloroethyl phosphate, tris (dichloropropyD-phosphate or to fix tris (2,3-dibromopropyl) phosphate.,

However, these measures only partially solve the problem, because the flame retardancy achieved is not permanent, as the additive evaporation or leaching over time is reduced, or it is imperfect, or the mechanical properties of the foams become undesirable as a result of formation Cracks and cavities severely impaired.

The production of polyisocyanurate foams containing urethane groups is also not new. Here, polyisocyanates are usually used in the presence of auxiliaries and catalysts cyclized and polymerized, and the isocyanurates and polymers obtained containing isocyanate groups are reacted with polyols. If necessary, it is also appropriate to use the tri or

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Carry out polymerization at the same time. Such polymer foams have a high temperature resistance, but only a relatively low flame resistance. Further the products are very brittle. The brittleness can be reduced by increasing the polyol content, which is disadvantageous is, however, that this simultaneously enhances the flame-retardant properties be reduced.

It was an object of the present invention to provide polyisocyanurate foams with low brittleness, high tear resistance as well as high temperature resistance and flame resistance.

It has been found that self-extinguishing urethane groups Polyisocyanurate foams with these advantageous Properties by reacting polyisocyanates with polyols in the presence of catalysts, blowing agents and, if appropriate Auxiliaries and additives can be produced if the polyisocyanate and the polyol are used in such proportions brings to the reaction that there are 6 to 60 NCO groups per hydroxyl group of the polyol in the reaction mixture and one as Polyol uses a polyesterol that is produced by condensation of aliphatic dicarboxylic acids with 4 to 12 carbon atoms and a diol mixture of optionally substituted and / or ether group-containing aliphatic diols with 2 to 18 carbon atoms and halogen-substituted aromatic diols of the formula

R ¹ R ¹ RNANR

in which:

A is a halogen-substituted phenylene, naphthylene or

Diphenylene radical,
R is an optionally substituted aliphatic radical having 1 to 4 carbon atoms which has at least one hydroxyl group

contains bound and
R ^{1 is} a hydrogen atom or an optionally substituted one

aliphatic radical having 1 to 4 carbon atoms.

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Surprisingly, you get there by using the above mentioned polyester oils in combination with the stated proportions between polyisocyanate and polyesterol to form polyisocyanurate foams, due to a very low brittleness, high thermal stability, high tear resistance and excellent flame retardant properties are excellent. These beneficial properties cannot be achieved if only the polyisocyanate is reacted with any polyol in the stated proportions, since the special polyesterol due to the content of aliphatic dicarboxylic acid and aliphatic diol, on the one hand, causes the resulting polyisocyanurate foam to be very low in brittleness and on the other hand, due to the content of halogen-substituted, nitrogen-containing aromatic diol, excellent flame resistance is achieved.

Organic isocyanates with a functionality of at least two are suitable for producing the self-extinguishing polyisocyanurate foams containing urethane groups according to the invention. Examples include aromatic polyisocyanates such as 2,4- and 2,6-tolylene diisocyanates, diphenylmethane diisocyanates, triphenylmethane triisocyanates, biphenyl diisocyanates, m- or p-phenylene diisocyanate and 1,5-naphthylene diisocyanates. Preferably used are the crude and pure toluene diisocyanates and mixtures of 2,2 ^f -, 2,4'- and 4,4'-diphenylmethane diisocyanate and polyphenyl-polymethylene polyisocyanates. The polyisocyanates can be used individually or as mixtures.

Catalysts for the cyclization and polymerization of isocyanates are known. Examples include: strong bases, such as quaternary ammonium hydroxides, for example benzyltrimethylammonium hydroxide; Alkali metal hydroxides, for example sodium or potassium hydroxide; Alkali metal alkoxides, for example sodium methylate and potassium isopropoxide; Trialkylphosphines, for example Triethylphosphine; Alky! Aminoalkylphenols, for example 2,4,6-tris (dimethylaminomethyl) phenol; 3- and / or 4-substituted pyridines, for example 3- or 4-methylpyridine; metal-

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organic salts, for example tetrakis (hydroxyethyl) sodium borate; Friedel-Crafts catalysts, for example aluminum chloride, iron (III) chloride, boron fluoride and zinc chloride and alkali metal salts, of weak organic acids and nitrophenolates, for example potassium octoate, potassium 2-ethyl hexoate, potassium benzoate, sodium picrate and phthalimide-potassium . The strongly basic N, N ^f , N ¹ '-tris (dialkylaminoalkyl) -s-hexahydrotriazines, for example N, N ^f , N ¹ ' -tris (dimethylaminopropyl) -s-hexahydrotriazine, are preferably used.

In many cases it is advantageous, in addition to the mentioned cyclization and polymerization catalysts to additionally use compounds that promote the formation of polyols and polyurethane Catalyze polyisocyanates. For example, tertiary amines, such as 1,4-diazabicyclo- (2,2,2) -octane and N, N-dimethylbenzylamine, are suitable, certain organic metal compounds such as stannous octoate and dibutyltin laurate and mixtures of tertiary Amines and tin compounds,

The appropriate amount of catalyst to make those of the present invention Polyurethane plastics is dependent on the effectiveness of the catalyst in question, in general it has it has been found to be expedient to add 1 to 15 parts by weight, preferably 3.5 to 10 parts by weight of catalyst for each To use 100 parts by weight of organic polyisocyanate.

Propellants that can be used in the process of the invention include water, which reacts with isocyanate groups to form carbon dioxide. The amounts of water that can expediently be used are 0.1 to 2 % _t based on the weight of polyisocyanate. If necessary, larger amounts of water can also be used, but preferably not if the thermal stability or the thermal insulation properties are of particular importance.

Other propellants that can be used are low-boiling liquids, which evaporate under the influence of the exothermic polymerization reaction. Liquids are suitable which are opposite are inert to the organic polyisocyanate and boiling points

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of not more than 100 ⁰ C at atmospheric pressure, preferably between -40 and +50 ⁰ C ₄ . Examples of such liquids, which are preferably used, are halogenated hydrocarbons, such as methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, dichloro-monofluoromethane, dichloro-tetrafluoroethane and l, l, 2-trichloro-l, 2,2-trifluoroethane, also mixtures of these low-boiling liquids with one another and / or with other substituted or unsubstituted hydrocarbons can be used.

The most appropriate amount of low-boiling liquid for the production of semi-rigid and rigid foams depends on the Foam density that you want to achieve, as well as the use of water, if necessary, in general deliver quantities from 5 to 40 percent by weight based on 100 parts by weight organic polyisocyanate, satisfactory results.

The reaction mixture can also contain auxiliaries and additives are incorporated »Stabilizers, for example, are Hydrolysis protection agents, pore regulators, fungistatic and bacteriostatic substances, dyes, pigments, Fillers, surfactants, plasticizers and flame retardants.

For example, surface-active substances which support the homogenization of the starting materials come into consideration serve and, if appropriate, are also suitable for regulating the cell structure of the foams Siloxane-oxyalkylene copolymers and other organopolysiloxanes, oxethylated alkylphenols, oxethylated fatty alcohols, Paraffin oils, castor oil or ricinoleic acid esters and Turkish red oil.

It can also be advantageous to include a plasticizer in the reaction mixture, so that the tendency to brittleness in the Products is reduced. Conventional plasticizers can be used, but it is particularly useful to use such To use agents that contain phosphorus and / or halogen atoms and thereby the flame resistance of the polyurethane plastics

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additionally enlarge = such agents include tricresyl phosphate, Tris-2-chloroethyl phosphate, tris-chloropropyl phosphate and tris-2,3-dibromopropyl phosphate "

In addition to the halogen-substituted phosphates already mentioned, antimony trioxide has proven particularly useful as a flame retardant, see above that preferably antimony trioxide in combination with the polyesterol which can be used according to the invention for flame-proofing the self-extinguishing polyisocyanurate foams containing urethane groups is used"

The essential features of the process according to the invention for producing the self-extinguishing polyisocyanurate foams containing urethane groups consist in the fact that the polyisocyanate and the polyol in such proportions for the implementation brings about that 6 to 60, preferably 10 to 40, NCO groups are present in the reaction mixture per hydroxyl group of the polyol and in particular that the polyol used is a polyesterol which is obtained by condensation of preferably an aliphatic Dicarboxylic acid having 4 to 12, preferably 4 to 6 carbon atoms or, if appropriate, mixtures of aliphatic dicarboxylic acids of the type mentioned with a diol mixture of optionally substituted and / or ether group-containing aliphatic Diols having 2 to 18, preferably 2 to 6, carbon atoms and halogen-substituted aromatic diols of the formula

R ¹ R 'RNANR

in the mean

A is a halogen-substituted phenylene-naphthylene- or preferably Diphenyl radical,

R is an optionally substituted aliphatic radical having 1 to 4 carbon atoms which has at least one hydroxyl group contains bound and

R ^{1 is} a hydrogen atom or an optionally substituted aliphatic radical having 1 to 4 carbon atoms,

will be produced. Mixtures of the aliphatic or aromatic diols can of course also be used.

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It is only essential that the polyesterol which can be used according to the invention of at least one aliphatic dicarboxylic acid and a diol mixture of at least one aliphatic diol and at least a nitrogen-containing, halogen-substituted aromatic diol is produced.

Examples of suitable aliphatic dicarboxylic acids for preparing the polyesterols are: glutaric acid, suberic acid, pimelic acid, azelaic acid, sebacic acid and preferably succinic acid and adipic acid. The dicarboxylic acids can be used individually or as mixtures. To prepare the polyester polyols, it may be advantageous, instead of the dicarboxylic acids to use the corresponding dicarboxylic acid derivatives such as dicarboxylic esters with 1 to ¹ J carbon atoms in the alcohol radical, dicarboxylic acid anhydrides or dicarboxylic acid chlorides.

Examples of optionally substituted and / or ether group-containing aliphatic diols are butanediol, hexanediol, neopentyl glycol, Dibromoneopentyl glycol »Preferably, however, glycol, propylene glycol and those containing ether groups are used Diols such as diethylene glycol, dipropylene glycol and triethylene glycol. Depending on the desired properties, the aliphatic Diols can be used alone or as mixtures in various proportions.

As examples of the nitrogen-containing, halogen-substituted, preferably chlorine- and / or bromine-substituted aromatic diols of the formula

R 'R ¹ RNANR

may be mentioned: the various isomeric N, N'-bis- (alkanol) -diaminooctachlorodiphenyls and N, N-bis (alkanol) diaminooctabromodiphenyls.

The N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl is preferably used, which is formed during the condensation of decachlorodiphenyl with monoethanolamine.

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The polyesterols which can be used according to the invention are prepared by known methods. Depending on the dicarboxylic acids used and the composition of the diol mixture of aliphatic and halogen-substituted aromatic diols, the polyesterols are liquid or solid and have more or less high chlorine and / or bromine contents. In order to obtain polyesterols that are liquid at room temperature and thus easily processable, diol mixtures are preferably used for esterification in which the molar ratios of halogen-substituted aromatic diol to _1, optionally substituted and / or ether group-containing, aliphatic diols 1: 1.3 to 10, preferably 1: 1.8 to 3. Particularly preferred polyesterols are, for example, condensation products of adipic acid, N, N'-bis- (2-ethanol) -diaminooctachlorodiphenyl and diethylene glycol and / or ethylene glycol and / or 1,2-propanediol.

The polyesterols which can be used according to the invention have molecular weights from 800 to 3000, preferably from 800 to 2000, and hydroxyl numbers from 140 to 35, preferably from 110 to 56.

The self-extinguishing polyisocyanurate foams containing isocyanate groups are produced according to the prepolymer and preferably the one shot process. To do this, mix the described manner obtained polyesterols with the polyisocyanates, Catalysts, propellants and, if appropriate, auxiliaries and additives in the stated proportions, intensive and then allows the reaction mixture to foam.

The self-extinguishing polyisocyanurate foams containing urethane groups obtained according to the invention have densities of 25 to 100 kg / m 2, preferably 28 to ⁵ kg / m 5 and are distinguished by their good mechanical properties and their excellent thermal stability and flame resistance. The products are preferably used as insulating material, for example in the construction sector.

The parts mentioned in the examples are parts by weight. The percentages relate to weight.

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Production of the polyesterols

A mixture of ethylene or propylene or diethylene glycol, N, N-bis ^f (ethanol-2) -diaminooctachlordiphenyl and adipic acid in a nitrogen atmosphere at I70 - 200 ⁰ C is condensed in the melt. The temperature of the melt is increased to the extent that the water of condensation is well distilled off. When most of the water of reaction has distilled off and the transition temperature has fallen somewhat, ^{the residual water is distilled off at 20O 0} C and gradually reduced pressure and condensation continues until the acid number of the polyester oil is less than 4 mg KOH / g 30 200 mm Hg depends on the aliphatic diol used and is to be selected so that no diol can distill off in the end phase of the condensation «

The type and composition of the starting materials and the chemical characteristics of the polyesterols obtained are as follows Table summarized:

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Tabel

Polyesterol

Raw materials

Hydroxy1-

value

(mg KOH / g)

Adipic acid 292 parts

Diethylene glycol 212 parts of N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl 548 pieces

Adipic acid
Diethylene glycol
N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl

Adipic acid
Ethylene glycol
N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl

Adipic acid
Diethylene glycol
N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl

Adipic acid
1,2-propanediol
N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl

1198 parts 722 parts

1753 pieces

1169 parts 410 parts

1644 pieces

II69 parts 658 parts

I698 parts

1169 parts 601 parts

1972 parts

95

91

Acid value
(mg KOH / g)

2.4

2.1

0.2

2.4

3.3

Cl

27

29

27

30th

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example 1

40 parts of the polyester oil A are added with stirring at room temperature

10 parts of antimony trioxide,
5.2 parts of N, N ^f , N '' - Tris- (dimethylaminepropyl) -s-hexahydro-

triazine

2.5 parts of a siloxane-polyoxyalkylene copolymer 25 parts of trichlorofluoromethane and

100 parts of a mixture of diisocyanatodiphenylmethanes and polyphenylpolymethylene polyisocyanates.

The reaction mixture is then allowed to foam. Man receives a polyisocyanurate foam containing urethane groups

with a density of 36.8 kg / m ⁵ , a flexural strength of

ο
3.75 kp / cm, a deflection of 7.1 mm and a compressive strength

2
speed of 2.49 kg / cm. The product has a low degree of brittleness

and is flame retardant.
Example 2

To a mixture of 40 parts of the polyester oil A and 22.5 Parts of trifluoromethane are added with stirring at room temperature

3 # 5 parts N, N ¹ , N '' - Tris-CdimethylaminopropylJ-s-hexahydro-

triazine,

2.5 parts of a siloxane-polyoxyalkylene mixture polymer and 100 parts of a mixture of diisocyanato-diphenylmethanes

and polyphenyl polymethylene polyisocyanates.

The reaction mixture is then allowed to foam. You get a polyisocyanurate foam containing urethane groups

with a density of 34.8 kg / m, a flexural strength of

2
3.60 kg / cm, a deflection of 9.0 mm and a compressive strength

2
speed of 2.68 kg / cm. The product has a low degree of brittleness

and is flame retardant.

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Example 3

To a mixture of 30 parts of the polyester oil B and 20 parts Trichlorofluoromethane is added with stirring at room temperature

7.5 parts of antimony trioxide

7 parts of N, N ¹ , N ¹ '-Tris-CdimethylaminopropylJ-s-hexahydrotriazine,

2 parts of a siloxane-polyoxyalkylene copolymer and 100 parts of a mixture of diisocyanato-diphenylmethanes and polyphenyl-polymethylene-polyisocyanates.

The reaction mixture is then allowed to foam. A polyisocyanurate foam containing urethane groups is obtained with a density of 36.0 kg / m, a flexural strength of 3.99

ο
kp / cm,. a deflection of 5.00 mm and a compressive strength

2
speed of 2.29 kp / cm. The product has a low level of brittleness

and is flame retardant.

example H

To a mix of

80 parts polyester B

80 parts of tris-ß-chloroethyl phosphate

8 parts of siloxane-polyoxyalkylene copolymer

14 parts of N, N ¹ , N ¹ '-Tris- (dimethylaminopropyl) -s-hexahydrotriazine, 100 parts of trichlorofluoromethane

400 parts of a mixture are added with stirring at room temperature from diisocyanato-diphenylmethanes and polyphenylpolymethylene polyisocyanates. The reaction mixture is then allowed to foam.

A polyisocyanurate foam containing urethane groups and having a density of 31.8 kg / m ³ and flexural strength is obtained

of 2.56 kp / cm, a deflection of 3.8 mm and a pressure

2
strength of 1.7 kp / cm. The product has a low degree of brittleness

and is flame retardant.

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Example 5

20 parts of the polyesterol C 5 parts of antimony trioxide

7 parts of N, N ', N' '- tris (dimethylaminopropyl) -s-hexahydrotriazine, 2 parts of a siloxane-polyalkylene copolymer and 20 parts of trichlorofluoromethane and

100 parts of a mixture of diisocyanatodiphenylmethanes and polyphenyl-polymethylene-polyisocyanates

are mixed intensively at room temperature. "Then leave to foam the reaction mixture. A polyisocyanurate foam containing urethane groups and having a density is obtained

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of 36 kg / m, a flexural strength of 2.81 kp / cm, one

ο deflection of 4.38 mm and a compressive strength of 2.02 kp / cm,

The product is a bit brittle and is flame retardant. Example 6

80 parts of the polyester D are diphenylmethanes diisocyanato-at 80 ⁰ C with 400 parts of a mixture of polyphenyl and polyisocyanurates reacted. A mixture is added at room temperature with stirring

80 parts of trichlorofluoromethane

40 parts of N, N ', N ¹ ' -Tris- (dimethylaminopropyl) -s-hexahydrotriazine - 8 parts of siloxane-polyoxyalkylene copolymer, 20 parts of antimony trioxide

The reaction mixture is then allowed to foam. A polyisocyanurate foam containing urethane groups is obtained

with a density of 35.5 kg / m ⁵ , a flexural strength of

2
2.99 kg / cm, a deflection of 5.3 mm and a compressive strength of 1.86 kp / cm. The product has a low degree of brittleness. It has a heat resistance of 247 ° C and is flame retardant »

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Example 7
To a mixture of 160 parts of polyester E.

160 parts of tris-ß-chloroethyl phosphate

8 parts of siloxane-polyoxyalkylene copolymer, 12 parts of N, N ', N ^f ' -Tris-idimethylaminopropylJ-hexahydrotriazine, 120 parts of trichlorofluoromethane

400 parts of a mixture are added with stirring at room temperature from diisocyanato-diphenylmethanes and polyphenyl-polymethylene-polyisocyanates. The reaction mixture is then allowed to foam.

A polyisocyanurate foam containing urethane groups is obtained

with a density of 39.0 kg / cm, a flexural strength of

ο
2.45 kp / cm, a deflection of 6.3 mm and a pressure

2 strength of 2.09 kg / cm “The product has a low

Brittleness and is flame retardant. Comparative example 1

The implementation of 40 parts of N, N'-bis (ethanol-2) -diaminooctachlorodiphenyl with 100 parts of a mixture of diisocyanatodiphenylmethanes and polyphenyl-polymethylene-polyisocyanates results in a urethane group-containing solid at room temperature Prepolymer used in the manufacture of polyisocyanurate foams is unsuitable.

Comparative example 2

To a mixture of 40 parts of a polyester oil made from adipic acid, Ethylene glycol and butanediol with OH numbers 56 and 20 Parts of trichlorofluoromethane are added with stirring at room temperature

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7 parts Ν, Ν ¹ , Ν ^! '-Tris-idimethylaminopropyD-s-hexahydrotriazine, 2 parts of a siloxane-polyoxyalkylene copolymer and 100 parts of a mixture of diisocyanato-diphenylmethanes and polyphenyl-polymethylene-polyisocyanates.

The reaction mixture is then allowed to foam. A polyisocyanurate foam containing urethane groups is obtained with a density of 37.6 kg / m, a flexural strength of 3.47 kg / cm, a deflection of 3.85 mm and a pressure

2
strength of 2.85 kp / cm. The product has a medium

Brittleness and is easily flammable. Comparative example 3

To a mixture of 10 parts of a chlorinated paraffin and 20 parts of a polyetherol made from trimethylolpropane and propylene oxide with the OH number'374 is added with stirring at room temperature

2.5 parts of antimony trioxide

7 parts of N, N ', N' '- Tris- (dimethylaminopropyl) -s-hexahydro-

triazine

2 parts of a siloxane-polyoxyalkylene copolymer and 20 parts of trichlorofluoromethane

100 parts of a mixture of diisocyanato-diphenylmethanes and polyphenyl polymethylene polyisocyanates.

The reaction mixture is then allowed to foam. A polyisocyanurate foam containing urethane groups and having a density of 41.6 kg / m ⁵ and a chlorine content of 5 percent by weight is obtained. The product is easily flammable.

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Claims (3)

Claims Ί. Process for the production of self-extinguishing polyisocyanurate foams containing urethane groups by reacting polyisocyanates and polyols in the presence of catalysts, blowing agents and optionally auxiliaries and additives, characterized in that the polyisocyanate and the polyol are reacted in proportions such that 6 to 6 per hydroxyl group of the polyol are reacted 60 NCO groups are present in the reaction mixture and the polyol used is a polyesterol which is obtained by condensation of aliphatic dicarboxylic acids with 4 to 12 carbon atoms and a diol mixture of optionally substituted and / or ether group-containing aliphatic diols with 2 to 18 carbon atoms and halogen-substituted aromatic diols formula Rt Rt R-N-A-N-R in the mean A is a halogen-substituted phenylene, naphthylene or diphenylene radical, R is an optionally substituted aliphatic radical having 1 to 4 carbon atoms which has at least one hydroxyl group contains bound and R 'is a hydrogen atom or an optionally substituted aliphatic radical having 1 to 4 carbon atoms, will be produced. 2. A process for the production of self-extinguishing polyisocyanurate foams containing urethane groups according to claim 1, characterized in that the molar ratio of halogen-substituted aromatic diol to optionally substituted and / or ether group-containing aliphatic diol in the polyesterol is 1: 1.3 to 10. - 17 - ο.ζ. 30 730 3. A process for the production of self-extinguishing polyisocyanurate foams containing urethane groups according to claim 1, characterized in that the polyesterol used is a condensation product of adipic acid, N, N'-bis- (2-ethanol) -diaminooctachlorodiphenyl and diethylene glycol and / or ethylene glycol and / or 1,2-propanediol is used. BASF Aktiengesellschaft 9/0804